When PayPal Express checkout is enabled in your NetSuite account, a new customer record is created each time the shopper uses express checkout.
A new shopper to your web store will generate a new customer record in Netsuite.
A shopper who already has a customer record in your NetSuite account will generate a new customer record when they checkout with PayPal Express.
Any duplicate customer records will appear in the list of customers with a number appended to the name. For example, if Jane Smith already has a customer record in the system, then a new record will appear with the name, Jane Smith1.
You can manage duplicate records by enabling the feature, Merge Duplicates from Setup > Enable Features > CRM. After that feature is enabled, you can periodically run the duplicate merge operation from the Search menu.
If customers click the PayPal Express Checkout button before logging in or registering in your site, a customer record is created, but they do not have login or password information saved and cannot access the Customer Center or My Account page.